When a non-interlaced RGB graphics signal used in computer systems is applied to video applications, like a TV, the non-interlaced RGB graphics signal is first converted to an interlaced YUV graphics signal, since computer systems display graphics signals in noninterlaced format which consists of contiguous horizontal scan lines, while video applications display video signals in interlaced format which is alternately comprised of odd fields and even fields. Moreover, since the refresh rate of video applications is only 30 frames per second in the NTSC standard or 25 frames per second in the PAL standard, which is far less than the 60 or 50 frames per second refresh rate of computer systems, flicker also occurs at the vertical edges or places having large brightness variation of adjacent horizontal scan lines in the output images when applying noninterlaced computer graphics signals to video applications.